NeuroNetFusion: enhanced EEG abnormality classification via multi-network TF-IDF feature selection

To address the inherent complexity and nonlinearity of electroencephalogram (EEG) signals, this study proposes a refined classification framework, NeuroNetFusion, which strategically integrates and selects multi-context network-based features for improved performance. This framework enhances the performance of bio-signal classification models by integrating multi-directionally expressed cross-dependence information. Unlike prior EEG classification studies that mainly relied on single-domain or uni-directional features, our framework introduces a systematic multi-context integration strategy, which constitutes a primary contribution of this work. The process begins with preprocessing the EEG signals using a Savitzky-Golay (SG) filter to reduce noise. Next, the signals are decomposed into multiple frequency bands using the Discrete Wavelet Transform (DWT). The resulting data are then reconstructed from five bands into corresponding adjacency matrices. Following this, the signals are represented as two distinct types of networks: a causality network based on the Directed Transfer Function (DTF) and a correlation network using the Pearson correlation coefficient. To combine features from these two networks, we utilize the TF-IDF method to vectorize the non-zero element index sequences from the adjacency matrices. This procedure transforms sparse adjacency matrices into a quantitative representation, allowing us to assess the importance of each connection within the network. Additionally, a genetic algorithm is employed to select important TF-IDF features, optimizing them for classification tasks. Performance is evaluated by comparing several conventional machine learning models using the EEG source dataset (MTOUH), employing standard evaluation metrics. The proposed model achieved a final accuracy of 88.05%, representing an 8.73% absolute improvement over the baseline TCN model. This demonstrates the effectiveness of our method in identifying abnormalities in EEG signals. The key contribution lies in bridging causality- and correlation-based representations through TF-IDF-driven feature encoding, offering a novel pathway for interpretable and scalable EEG analysis. Our approach holds promise for future applications in cross-dependent bio-signal classification problems, paving the way for further research and development in this area.